Locking latch assembly



April 11, 1961 H. HESLER LOCKING LATCH ASSEMBLY Filed April 2, 1958 INVENTOR. HAROLD HEISLER ATTO R NEY United States Patent LOCKING LATCH ASSEMBLY Harold Heisler, Lombard, Ill., assignor to Midwest Folding Products Mfg. Corp., Roselle, lll., a corporation of Illinois Filed Apr. 2, 1958, Ser. No. 725,836 i 8 Claims. (Cl. 7057) table. In that environment, the pivotally connected elements comprise links movable through substantially 180 with respect to each other to support the tabletop in its open, horizontal position, and to permit the top to be folded for storage. table open, prevents collapse or folding thereof.

An object of this invention is to provide a latch assem bly `having utility, for example, in the environment of,`

the table described. Another object of the invention is in the provision of a locking latch having a plurality of operating conditions-namely, one in which the latch is unlocked so that the structures controlled thereby may be moved between the open and closed positions thereof` simply by releasing the latch; another in which the latch is locked While the structures are closed whereby they cannot be moved to open position; and a third in which Ithe latch is locked when the structures are in the open position thereof, but nevertheless can be moved to their closed position and are then automatically locked.

Still another object of the invention is that of providing alockng latch of the character described, wherein the locked and unlocked conditions thereof are readily determined by the stability of the latch, it being free to iiop about when locked and is maintained in one prei determined position when unlocked. Additional objectsand advantages of the invention will become -apparentas the specification develops. t

An embodiment of the invention is illustrated in the accompanying drawing, in which Figure l is a side view in elevation of a locking latch assembly embodying the invention; Figure 2 is a side view in elevation of the apparatus shown in Figure l, but

with the pivotally movable members thereof rotating toward the closed position of Figure l; Figure 3 isa 155 rear view in elevation ofthe apparatus, but with the inner member thereof being pivoted into open position; Figure 4 is an enlarged, .broken vertical sectional view` ofthe apparatus in whichthe latch is shown by full lines in the locked condition. thereof, and by broken linesiin its unlocked condition; and Figure 5 is an enlarged, broken vertical sectional view .similar to that of Figure 4,` but showing the structure; in its unlocked and'` unlatched condition.

The latch structure `especially suited` for use in cor1` junction withtelements that are supported .in pivotal relation to'eaclr other, andare desirab-ly latchable in one-c The latch, when locked with the` of their-.relative positions which for convenience may be termed the closed condition thereof. In the drawing, the

exemplary structure comprises inner andouter, channel members 10 and 11.

The channel 10V is generally Ueshaped, is provided withra base wall 12 haying an x opening 13 formed therein. The outer channel 11 is also generally U-shaped, and has a base wall 14 provided with an opening'lS therein generally aligned with the opening 13. The channel 11 is dimensioned so Ias to be nestingly receivable within the outer channel 11, and the members are pivotally connected by a pin 16 that extends across the channels and through the respectively adjacent legs thereof. l

The channels are relatively movable between the closed position thereof shown in Figures 1, -4 and 5, through the partially opened position shown :in Figure 2, and into the completely open state illustrated in Figure 3. It is seen that when the channels are closed, the upper edge 17 of the opening 13 is oriented at substantially the mid-portion of the opening 15, but the lower edge 18V thereof extends slightly below the lower edge of the opening 15. The opening 15 is provided centrally along the lower edge 19 thereof with an upwardly extending tongue 20 which is slightly narrower than the openings 13 and 15. Extending outwardly from the base wall 14 of channel 11 are a pair of ears 21 and 22, one on each side of the opening 15. The ears are aligned and have a` pivot pin 23 extending therebetween.

Pivotally mounted on the pin 23 is a pair of latch lingers 24 and 25 delined by the spaced legs of a generally U-shaped latch member having a base wall 26. A spring 27, seated at one end thereof on the tongue 20, extends upwardly beneath the pivot pin 23 and at its other end seats upon the base wall 26 of the latch member. The spring may be a coil spring wrapped about the pin 23 or an ordinary leaf spring, and in either event is operative to bias the latching fingers 24 and 25 into the position thereof shown in Figure 4, wherein they extend through the opening 13 of the inner channel and interlock therewith by receiving and seating the edge portion 17 within `a notch or recess 28 formed in each of the latch fingers. The latch lingers adjacent the recess 2S are each provided with a downwardly and inwardly inclined cam surface 29.

Also pivotally supported on the pin 23 is a generally U-shaped actuator lever 30 having side walls or legs `depressed inwardly as shown at 31 to enable the same to be disposed between the ears 21 and 22. The actuator" is substantially wider than the U-shaped latch member, which is partially disposed therewithin andas a result is freely pivotal with respect thereto about the pin 23. The base wall 32 of the actuator is equipped with a lock 33 adapted to be controlled and manipulated by a key (not shown). The lock 33 may be entirely conventional with` respect to the key manipulation thereof, and therefore such details of the lock need not be illustrated and described. The lock is equipped with a threaded tubular portion 34 that extends through the base wall 32 of the actuator and receives a fastener 35 such as a ,Truarc ring, seated in a recess in the lock body which bears against the base wall and secures the lock in position" thereon. The lock also has a spindle 36V that is rotated by manipulation of the key, and the spindle carries at`,

its outer enda lug 37 that can be rotated between the unlocked position shown by full lines in Figure 5, and

the locked position illustrated by the broken lines in1 Figure 5.

Through comparison of Figures 4 and 5, it is evident that the latch iingersf24 and 25 are pivotal about the pin 23 between the latching positionof Figure-4 and the unlatched position of Figure 5. The leat` spring 27 biases `the latch fingers toward the `position shown in Figure 4,

and movement thereof to the unlatc'hed'position must be effected by rotating'the same in a` counter-clockwise direcl tion about the `pin 23. Such movement can be enforced by pressing theupper end of the actuater 30toward the l base wall 14Aof "the outer channel, for such movement imposes a counterclockwise torque yon the latch fingers through the connection thereof with the lug 37 of lock 33, as shown in Figure 5.

it is vevident that the channels '10 4and 11 cannot lbe pivoted with respect to each o therwhen the latch fingers are in the locking position of Figure 4 because the pivot pin 23 and lower edge portion 17 of the inner channel lie along Aa common plane; and thus, any force tending to move the channels relative to eachother is exerted between the pivot pin 23 and latch fingers at their points of engagement with the channel edge '17, and therefore is'ineffective to cause relative movement of the channels. However, when the actuator 30 is pressed into the position shown in Figure 5 to release t-he latch lingers 24 and 25, the channels are freely movable with respectto each other.

`When the lock 33 is released, the lug 37 is aligned with the base wall 26 of the latch finger structure, as shown by full lines in both Figures 4 and V5. The latch may now be released simply by pressing the actuator 30 inwardly as heretofore described, with the Vresult that the channel members and `11 are freely movable between the `open and closed positions thereof. However, in locked position, the lug 37 is rotated through approximately 180 and into the position shown by dotted lines in Figures 4 and 5. At such time, the actuator 30 is free to pivot about the pin 23 independently of the latch fingers 24 and 25 Vfor there is then no interconnection between these two elements. This freedom of movement of the actuator is shown by broken lines in Figure 4. At this time then, the channels are locked in their closed position and cannot be moved until the lock 33 has been manipulated by the key therefor.

If the channel members are moved to the openrposition thereof, and the element 33 is locked (that is, the lug 37 is rotated free of the latch finger base wall 26), the channels can be rotated vinto their closed position and are automatically locked thereat, the reason for this -of course being that the actuator 30 has lost control of the latchingV fingers 24 and 25. The cam surfaces 29 ofthe latch fingers perform an important functionV in permitting 'the channel members to be moved to their closed position, for such surfaces engage the edge portion 17 of the inner channel, whereupon the latch fingers are .progressively rotated in a counter-clockwise direction about the pivot pin 23 to permit the insertion thereof through Ythe opening 13 of the inner channel. When once inserted through Y that opening, Vthe leaf spring 27 snaps the latch fingers into Jthe* locking position thereof, asshown in Figure .4.v

lThe feature of permitting Athe latch apparatus to be locked when the channels 10 and 11 are open is advantageous, especially in the foldable table :environment rethe linvention has been disclosed in considerable detail forpurposes of adequatelyrdescribing they same, it will be apparent'to those skilled in theart thatgnumerous changes may be made in those details without departing from the spirit yand principles of'theinvention. I claim: v- 1 j f 1. In a lockable "latchfstructure forv use insselectively constraining relative movement of agpair-of pvotally connectedrchannel members, anfouter ygenerally vU-'shaped vchannel-pr'ovidedfwith anlopeningin the base .wall there-pV of and having a pair ofearsextending outwardly from the-base /wall :along 'opposite sides of said opening,A an

' Y inner Vgenerally U'sha'ped channel pvotally supported y Y lwithirrfsaid.outerchannel-fifswinging movement relative l5 a generally U-shaped rr'le'mberhaving a base wall' and afar-asas thereto and being provided with an opening in the base Wall thereof, the base wall of said outer channel being provided with a tongue extending upwardly into the opening thereof, a pivot pin extending between said ears, a generally U-shaped member having a base wall and spaced apart latch fingers extending therefrom and being v mounted on said pivot pin for pivotal movement thereabout, said latch fingers each being provided with a recess along the upper edge thereof adapted to seat the upper edge portion vof said second mentioned opening therein when the latch fingers extend through such opening, spring means biasing said latch fingers toward said edge portion to seat the same within said recesses, a generally U-shaped actuator pvotally/supported upon said pin and receiving the base wall of said U-shaped member between the legs thereof, and a lock carried by said actuator and being equipped with a lug engageable with the base wall of said U-shaped member when the lock is in its unlocked condition but being disengaged therefrom when in locked condition, said lug when engaging the base wall of said U-shaped member being effective to pivot such member in a direction to release the latch fingers when the actuator is rotated in the same `direction about said -pivot pin and being ineffective to tion of the inner channel to latch the same when the inner channel is swung into said outer channel.

2. In a lockable latch structure for use in selectively constraining relative movement of a pair of `pvotally connected channel members, an outer generally U-shaped channel provided with an opening in the base wall thereof and having a pair of ears extending outwardly from tlle base wall along opposite sides of said opening, an inner generally .LJ-shaped channel pvotally supported within said outer channel for swinging movement relative thereto and being provided with an opening in the base wall thereof, the base wall of said outer channel being provided withl a tongue extending upwardly into the opening thereof, aY pivot pin extending lbetween said ears, Ya generally U-shaped member having a base wall and spaced apart latch fingers extending therefrom and being mounted on said pivot pin for pivotal movement thereabout, said latch fingers each being provided with a recess along the upper cdge thereof adapted to seat the upper edge portion of said second mentioned opening therein when the latch fingers extend through such opening, spring means biasing said latch fingers toward said edge portion to seat the same within said recesses, a generally U-shaped actuator pvotally supported upon said pin andv receiving the base wall of said U-shaped member between the legs thereof, and a lock carried by `said actuator and being equipped with a lugengageable with the base wall of said U-shaped member when the lock is in its unlocked condition but being disengaged therefrom when in locked condition, said lug when engaging the base wall of said U-,shaped member being effective to pivot such'member thereto and being provided with Yan opening in the'base i wall thereof, the base wall of said outer channel being provided with a tongue extending upwardly into the 3. In a lockable latch structure for use in selectivelyV constrainingrelative movement of `a pair of pvotally connected channel members, an outer generally U-shaped channel provided with an .opening in the base wall'thereof and having a pair of ears extending outwardly from the base wall along opposite sides of said opening,r an

inner generally U-shaped channel pvotally supported L within said outer channel for swinging movement relative opening thereof, a pivot pin, extending between said ears',

spaced apart latch fingers extending therefrom and being mounted on said pivot pin for pivotal movement thereabout, said latch fingers each being provided with a recess along the upper edge thereof adapted to seat the upper edge portion of said second mentioned opening therein when the latch fingers extend through such opening, spring means biasing said latch fingers toward said edge portion to seat the same within said recesses, an actuator pivotally mounted upon said pin, and a lock carried by said actuator and being equipped with a lug engageable with the base wall of said U-shaped member when the lock is in its unlocked condition but being disengaged therefrom when in locked condition, said lug when engaging the base wall of said U-shaped member being effective to pivot such member in a direction to release the latch fingers when the actuator is rotated in the same direction about said pivot pin and being ineffective to pivot such member when disengaged from the base wall thereof.

4. ln a locking latch structure for use in selectively constraining relative movement of a pair of pivotally connected members, a first member having a base wall provided with an opening therein and having a pair of ears extending outwardly from the base wall along opposite sides of said opening, a second member having a base wall provided with an opening therein and being pivotally connected to said first member formovement between a closed position wherein said base Walls are in adjacency and an open position wherein said base walls are separated, said openings being in communication with each other when said members are closed, a pivot pin extending between said ears, a latch finger pivotally supported upon said pin for pivotal movement therep about and being extensible through said openings and having a recess adapted to seat a portion of the base wall of said second member therein, means biasing said latch finger toward such engagement with said second member, an actuator pivotally supported by said pin, and a lock carried by said actuator and having a lug engageable with said latch finger when said lock is in its unlocked condition to pivot the latch finger in one direction into a position of escapement from said second member when the actuator is rotated in the same direction about said pin, said lug being moveable into a position of disengagement with said latch finger when said lock is operated to the lock position thereof so that when said actuator is pivoted, said lug is ineffective to pivot said latch finger.

5. The apparatus of claim 4 in which said means comprises a spring.

6. The apparatus of claim 4 in which a second latch finger is provided, and in which a base wall-interconnects Said latch fingers, said lug being engageable with said last-mentioned base wall to effect the aforesaid engagement of said lug with said latch finger.

7. The apparatus of claim 4 in which said latch nger is equipped with an inclined edge at the forward portion thereof functioning as a cam to pivot said latch finger into a position affording insertion thereof into the opening of said second member when the members are moved to the closed position thereof.

8. In a locking latch structure for use in selectively constraining relative movement of a pair of pivotally connected members, a first member having a base wall provided with an opening therein, a second member having a base wall provided with an opening therein and being pivotally connected to said first member for movement between a closed position wherein said base walls are in adjacency and an open position wherein said base walls are separated, said openings being in communication with each other when said members are closed, a pivot pin carried by said first member along the opening therein, a latch finger pivotally supported upon said pin and being extensible through said openings and having a recess adapted to seat a portion of the base wall of said second member therein, means biasing said latch linger toward such engagement with said second member, an actuator pivotally supported by said pin, and a lock carried by said actuator and having a lug engageable with said latch finger when. said lock is in its unlocked condition to pivot the latch finger in one direction into a position of escapement from said second member when the actuator is rotated in the same direction about said pin, said lug being movable into a position of disengagement with said latch finger when said lock is operated to the lock position thereof so that when said actuator is pivoted, said lug is ineffective to pivot said latch finger.

References Cited in the tile of this patent UNITED STATES PATENTS 1,960,410 Christensen May 29, 1934 2,010,492 Karre Aug. 6, 1935 2,167,009 Skobel July 25, 1939 2,333,861 Harden Nov. 9, 1943 2,710,535 Quinn June 14,1955

FOREIGN PATENTS 1,023,697 Germany Jan. 30, 1958 

